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GETMAIN



Assembler


Description

The GETMAIN command invokes the GETMAIN macro and allocates virtual storage. At least one parameter (n, nK, LA= length address, LV= length value) must be specified with the GETMAIN command. Then, any number of optional parameters can be specified. The address will be stored in register 1 if no address parameter is specified, and the return code is stored in register 15. A record of the command is written to the session log.

Input

image2021-2-15_18-7-36.png

The following are the parameter descriptions for the GETMAIN command:

n

The length in number of bytes.

nK

The length in number of bytes times 4096.

LA=length address

The address or general-purpose register number containing the address of a fullword length. Enclose a register number in parentheses.

LV=length value

The length in number of bytes or general-purpose register number containing a length in number of bytes. Enclose a register number in parentheses.

A=

The address, label, or general-purpose register number containing the starting address of the acquired storage. If address is not specified with the A= parameter, the default is register 1. Enclose a register number in parentheses.

BNDRY=

Alignment of the acquired storage. DBLWD is the default.

INIT=

The initialization of the acquired storage. Valid values for character are 00 - 99 and A - Z. The default is 00.

LOC=

Location of the acquired storage with reference to the 16MB line. BELOW is the default.

SP=

A subpool number from 0 - 127 or general-purpose register number containing a subpool number. Enclose a register number in parentheses. The default subpool is 0.

Usage Notes

  1. When the GETMAIN command is entered with a register number specified for the A= parameter, that register and register 15 are updated in the GPREGS or Keep window.
  2. SHOW REGION does not display the updated storage information until a page boundary (4096K) is met, even after you enter the GETMAIN command.

Examples

  1. To acquire 198 bytes of storage above the line using subpool 2, enter:
       GETMAIN 198 LOC=ABOVE SP=2
  2. To acquire 4096 bytes of storage below the line and initialize with character “Z”, enter:
       GETMAIN 1K INIT=Z

  3. To acquire storage with the length in register 9 and return the acquired storage location in register 3, enter:
       GETMAIN LA=(9) A=(3) LOC=ANY
    The following figure shows an example of entering the GETMAIN command to acquire storage.
    Entering the GETMAIN Command 

    ---------------------------- CODE DEBUG TSO - SOURCE --------------------------
    COMMAND ===> getmain 198 sp=123                                SCROLL ===> CSR
    PROGRAM: ASMRENT    MODULE: ASMRENT   COMP DATE: 07/29/1995  COMP TIME: 14.41.00
    000095    SAVEAREA DS    0D                   >  0                    DBLWORD
            ** END **

    ------   ------------------------------------------ Before ASMRENT:27/AMODE 24 <>
    000009             LR    R12,R15            *
    000010             DROP  R15                *     OPEN UP
    000011             USING ASMRENT,R12
    000012             USING WORKSTOR,R4
    000013             L     R0,WORKSIZE
    000014             GETMAIN RC,LV=(0)
    000024             LTR   R15,R15
    000025             BNZ   ENDRTN
    000026             LR    R4,R1
    =====>             LA    R11,SAVEAREA        *
    000028             ST    R13,4(R11)          *    CHAIN SAVE AREAS
     GPREGS  R0  ==> 00000198 R1  ==> 800800F8 R2  ==> 80077BFC R3  ==> 0005AC30
             R4  ==> 0003C108 R5  ==> 0003C850 R6  ==> 00000000 R7  ==> 800491F6
             R8  ==> 0008DFF4 R9  ==> 00000198 R10 ==> 0004935C R11 ==> 00000000
             R12 ==> 0007FAC8 R13 ==> 0008DFA8 R14 ==> 0007DA4C R15 ==> 0003C0F8

    The following figure shows the result of entering the GETMAIN command. The starting address of the acquired storage is stored in register 1 and the return code is stored in register 15.

    Result of Executing the GETMAIN Command 

    ----------------------------- CODE DEBUG TSO - SOURCE ------------------------
    COMMAND ===>                                                   SCROLL ===> CSR
    PROGRAM: ASMRENT    MODULE: ASMRENT   COMP DATE: 07/29/1995  COMP TIME: 14.41.00
    000095    SAVEAREA DS    0D                   >  0                    DBLWORD
            ** END **

    ------   ------------------------------------------ Before ASMRENT:27/AMODE 24 <>
    000009             LR    R12,R15            *
    000010             DROP  R15                *     OPEN UP
    000011             USING ASMRENT,R12
    000012             USING WORKSTOR,R4
    000013             L     R0,WORKSIZE
    000014             GETMAIN RC,LV=(0)
    000024             LTR   R15,R15
    000025             BNZ   ENDRTN
    000026             LR    R4,R1
    =====>             LA    R11,SAVEAREA        *
    000028             ST    R13,4(R11)          *    CHAIN SAVE AREAS
     GPREGS  R0  ==> 00000198 R1  ==> 0003C108 R2  ==> 80077BFC R3  ==> 0005AC30
             R4  ==> 0003C108 R5  ==> 0003C850 R6  ==> 00000000 R7  ==> 800491F6
             R8  ==> 0008DFF4 R9  ==> 00000198 R10 ==> 0004935C R11 ==> 00000000
             R12 ==> 0007FAC8 R13 ==> 0008DFA8 R14 ==> 0007DA4C R15 ==> 00000000

 

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